A Proposal for the Inclusion of Calorimeters in Animal Experiments in Which the Physical Activity is a Pivotal Theme : A Pilot StudyA Proposal for the Inclusion of Calorimeters in Animal Experiments in Which the Physical Activity is a Pivotal Theme : A Pilot Study身体活動量が重要テーマである動物実験における活動量計使用の提言：パイロット研究

As in clinical studies concerning the exercise that is effective to control life-style diseases, the energy expenditure is a pivotal item, so experiments usingcalorimeter have been started in Japan. It had been found by Ichikawa et al（ 1987） that the profile of energy expenditure in laboratory rats in cages is virtuallyidentical to that of very sedentary elderly persons living in nursing homes. However, into animal experiments especially in rodents, neither pedometer nor calorimeterhas been introduced. Recently, the usefulness of a pedometer designed for humans was proven in rats （Sasaki, 2015）. In the present study, with Panasonic EWNK32,in rats living in usual cages, 24-h measurements of both physical activity related energy expenditure （AEE） and total amount of energy expenditure （TEE） were executed. AEE and TEE was divided into twoportions; that of the 1st day（ AEE-YD） : that of the 2nd day （AEE-TD） and TEE-YD : TEE-TD, respectively. AEE-YD and AEE-TD was 40.4 and 33.8KJ, respectively. AEE-YD／AEE-TD was 119.7％（ p<0.05）. TEE-YDand TEE-TD was 197.0 and 117.2KJ, respectively. TEE-YD／TEE-TD was 168.7％（ p<0.05）. AEE/day／TEE/day was 23.6％. Although, the accuracy of real values may be called into question, ratios between items werethought to be meaningful; AEE-YD／AEE-TD and TEE-YD／TEE-TD may reflect the circadian rhythm in physical activity in rats. The present study would form the basis for the development of the pedometer orcalorimeter specific for rodents, and knowledge obtained from experiments using such devices would contribute to control not only life style diseases but also dementiafollowing bedridden state.